Alcohol and car accidents

Introduction

According to National Public Radio (NPR), alcohol consumption has been increasing in the United States, and our group wants to explore how this change may be related to the frequency of car accidents. One of the data sets we are using to examine this issue is “Drivers Involved in Fatal Crashes, by State and Blood Alcohol Concentration of the Driver” (source). This data covers the United States, up to the year 2017, and was collected by the Fatality Analysis Reporting System.

Summary Paragraph

For our datasets, the datasets we used gave every car accident for a certain state/region for a given year. For our chosen set, it reported every accident in New York from 2014 to 2016. The summary information that we calculated was the number of accidents per year, the number of accidents with alcohol has a cause, the percentage of accidents caused by alcohol, average accidents per year, and most common day car type. From 2014 to 2016, New York had 1048575 crashes and 11641 were caused by drivers under the influence of alcohol. This is a large number of car accidents due to alcohol consumption, but it was only 1.11% of the total crashes in New York. While it is only a small percentage of New York’s total crashes, the number itself is significant and can be reduced when people cease drunk driving. On average, New York had 524287 crashes per year, and the year with the highest crashes was 2016, showing that the number of crashes has not been decreasing.

Summary Table

This table shows the total drivers involved in fatal car accidents up to 2017 and the percentage of drivers that had a Blood Alcohol Content (BAC) greater than or equal to 0.1 by state. The table is arranged by decreasing number of fatal deaths. This information is displayed to show how many fatal crashes can be reduced if drivers are responsible and do not drunk drive.

State Number of Drivers Involved in Fatal Crashes Percent of Drivers w/ BAC Greater Than or Equal to 0.1
Texas 5204 33
California 5045 25
Florida 4614 21
Georgia 2283 18
North Carolina 2004 23
Pennsylvania 1698 21
Ohio 1677 22
Illinois 1570 26
Michigan 1488 23
Tennessee 1451 20
Arizona 1375 23
New York 1361 25
South Carolina 1359 26
Missouri 1321 22
Indiana 1309 18
Alabama 1249 24
Virginia 1163 23
Kentucky 1086 19
Louisiana 1041 24
Colorado 940 22
Mississippi 934 16
Oklahoma 926 20
New Jersey 865 18
Wisconsin 836 26
Washington 817 25
Maryland 781 25
Arkansas 687 23
Kansas 623 17
Oregon 590 25
New Mexico 534 25
Minnesota 533 20
Massachusetts 469 29
Nevada 455 21
Iowa 450 21
West Virginia 398 20
Utah 395 14
Connecticut 376 35
Idaho 326 21
Nebraska 316 21
Maine 251 23
Montana 228 26
Delaware 174 21
South Dakota 158 27
North Dakota 146 34
Wyoming 145 28
Hawaii 144 32
New Hampshire 142 20
Alaska 103 24
Rhode Island 103 37
Vermont 93 23
District of Columbia 38 44

From the table, one can see that a high percentage of states’ fatal car crashes are due to drivers with a BAC greater than or equal to 0.1. The top three states by number of fatal crashes are Texas, California, and Florida. But the table also shows that the state size (population) correlates to the number of accidents. The most important takeaway is knowing that roughly NA% of fatal car crashes in all states is due to drunk driving, meaning that these crashes are all preventable if drivers act responsibly.

Charts

The bar plot below displays the percentage of adults involved in car accident fatalities in the United States sorted by BAC (Blood Alcohol Concentration). The three bars have information at the 0, 0.1-0.7, 0.8+ BAC levels respectively.

As can be seen, this chart clearly depicts how the the highest frequencies in adult fatalities were at the 0.0 BAC level and 0.8+ level. This shows that there were more US adults involved in these car accidents when they were legally impaired(0.8+), as compared to intoxicated at a BAC level ranging from 0.1-0.7. Clearly, the most extreme BAC levels have led to some of the highest percentage of adults involved in these car accident fatalities.

The next chart includes multiple graphs of fatal car accident percentage by age and gender accross the United States. This chart intend to show “The relationship between driving under the influence and age/gender in 2012 and 2014.”

From these graphs, we can see that female drivers are less likely to be involved in fatal drunk driving accidents across the United States, while drivers between the ages of 21 and 35 are most likely to be involved in fatal drunk driving accidents. Overall, states like MT, ND, WY, and NM have higher drunk driving death rates, and states like WA, MI and UT have lower death rates. This general trend hasn’t changed from 2012 to 2014.

This third chart was intended to show the relationship between drivers involved in fatal crashes with zero blood alcohol content compared to those who were over the legal limit of 0.08 BAC. This makes an effort to answer, “Is a driver with higher blood alcohol concentration (BAC) more likely to be involved in a crash?” Each point represents a state.

Here, we see that in most states, over 70% of drivers involved in fatal crashes were sober (had blood alcohol content of 0), shown on the right half of the plot. There are a few exceptions, shown on the left half of the plot, where there is a lower percentage of sober drivers in accidents and a higher number of drivers over the legal limit.